Protecting fuel delivery systems in engines combusting ethanol-containing fuels

ABSTRACT

The present disclosure relates to the use of fuel additives in duel delivery systems contacting or combusting fuels containing ethanol, such as E85. The additives improve the properties of the resulting fuel, minimize the impact of the fuel on the components of the fuel delivery system, improve the protection of the engine and the fuel delivery system, and also enhance the benefits to the consumer and to the environment of utilizing varying amounts of ethanol as a fuel in combustion engines.

FIELD

The present disclosure relates to the use of fuel additives in dueldelivery systems contacting or combusting fuels containing ethanol. Theadditives improve the properties of the resulting fuel, minimize theimpact of the fuel on the components of the fuel delivery system andalso enhance the benefits to the consumer and to the environment ofutilizing varying amounts of ethanol as a fuel in combustion engines.

BACKGROUND

Much has been said about the use of ethanol as a fuel by itself, andalso as a blend component for use with gasoline, and even with dieselfuels. Ethanol can be produced from crops and thus provides a viablerenewable fuel source.

A common blend of gasoline and ethanol being discussed is 15% gasolineand 85% ethanol, often commonly referred to as “E85” fuel (hereinafter“E85”). Other ethanol fuels can comprise, for example 10% ethanol (E10)and 100% ethanol (E100).

The use of ethanol alone or in gasoline blends can create new problemsfor fuel equipment designed to handle the more non-polarhydrocarbonaceous petroleum fractions commonly known as gasolines. Thepolarity, corrosivity, adhesiveness, friction properties, and perhapsconductivity of ethanol or ethanol-containing fuel can create newproblems and new needs in the fuel industry.

E85, gasoline, and diesel are seasonally adjusted to ensure properstarting and performance in different geographic locations. For example,E85 sold during colder months often contain only 70% ethanol and then30% petroleum additives to produce the necessary vapor pressure forstarting in cold temperatures. During warmer months the petroleumadditive content for E85 can often be, for example, 17% to about 20%.However, as the interest increases to other fuel blends and to possiblywider use of E100, the need for better cold start performance andreliability will increase.

Commercial ethanol is widely treated with additives designed to preventhuman consumption. Such treated ethanol is called denatured alcohol, ordenatured ethanol and common denaturants include gasoline, gasolinecomponents, and kerosene. Other denaturants for rendering fuel alcoholunfit for beverage use are defined in 27 CFR 21.24.

Fuel delivery systems in vehicles combusting gasoline fuels haveincreasingly complicated componentry, some of which is, can be or willbe highly sensitive to variations in certain fuel parameters. Physicaland chemical properties of the fuel can negatively impact theperformance or life of these fuel delivery systems. Thus, certaincomponents designed for use in traditional gasolines might besusceptible to fatigue, reduce performance or complete failure uponprolonged exposure to fuels containing ethanol, particularly fuelscontaining high percentages of ethanol, like E85 and E100. Therefore, aneed exists to protect such older engines and well as improve thereliability of newer engines when all are exposed to prolongedcombustion of ethanol-containing fuels.

As currently offered to consumers by several automakers, flexible fuelvehicles (FFVs) are designed to operate on any mixture of gasoline andethanol—with ethanol concentrations of up to 85% by volume (E85). Thereis one major difference between an FFV and a conventionalgasoline-fueled vehicle—the FFV detects the ethanol/gasoline ratio andmakes appropriate adjustments to the engine's ignition timing andair/fuel mixture ratios to account for the ethanol and optimizeperformance and maintain emissions control. The vehicle must be equippedwith an air/fuel ratio map capable of handling the adjustments necessaryfor optimized performance on both gasoline and E85. Components of thefuel delivery systems on FFVs are also modified and upgraded to beresistant to the corrosive effects of alcohol in the fuel.

Much like gasoline, the volatility of E85 must be adjusted seasonallyand by geographic region to assure adequate cold start and drive awayperformance. This is done by increasing the amount of gasoline(typically from 15% to 30% by volume) in blends sold during coldermonths.

Pure ethanol has broader flammability limits than gasoline and burnswith lower flame luminosity. When blended with hydrocarbon fuels, thevapor space flammability limits of ethanol approach those of gasolineand luminosity is increased.

OGA-480, a polyetheramine available from Chevron Oronite, has been usedin E100 fuel but has not been used in E85, nor have other amines beenused in ethanol/gasoline blends, to the knowledge of the presentinventors.

SUMMARY OF THE EMBODIMENTS

An embodiment presented herein provides fuel additive agents for use inimproving the protection of fuel delivery systems of engines combustingethanol-containing fuels, including but not limited to E100, E85, E50,and the like down to E10 and trace blends of ethanol in gasoline.

Another embodiment provides a method to improve protection of a fueldelivery system in an internal combustion engine, said method comprisingdelivering to and/or combusting in said engine a fuel compositioncomprising gasoline, ethanol and at least one fuel additive.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are intended to provide further explanation of the presentdisclosure, as claimed.

DETAILED DESCRIPTION OF EMBODIMENTS

By “ethanol” herein is meant ethyl alcohol, the chemical compoundC₂H₅OH. This can arise in or be provided in many qualities or grades,such as a commercial blend or fuel grade, as well as pure or reagentgrade ethanol, and can be derived from any source such as but notlimited to petroleum refinery streams, distillation cuts, andbio-derived (e.g. bioethanol from corn).

By the present disclosure herein is provided a method for improving theprotection of internal combustion engines and the fuel delivery systemused to convey and deliver the fuel to the combustion engine. Inparticular, the problems that can arise in the delivery and combustionof fuels containing ethanol, and especially high levels of ethanol areaddressed by the embodiments within the present claims. The more polarnature of the ethanol as compared to the less polar hydrocarbonaceousgasoline can have a negative impact on, for example, the parts of theengine's combustion surfaces, fuel tank, valves, seals, gaskets,injectors, liners, pumps, hoses, liners, filters, and other components.In addition, the ethanol used in the ethanol-gasoline blends of thepresent disclosure is not necessarily or always pure ethyl alcohol butcan and will often contain certain varying amounts of sulfur andsulfur-containing chemicals, acidic or basic components or contaminants,water, possibly ethylene glycol, other alcohols, and petrochemicalfractions boiling near ethanol. In addition, when the ethanol isbio-derived, the bio-source can contribute other natural products andbio-derivatives which can accumulate in or on vulnerable engine and fueldelivery parts. The present disclosure provides fuel compositions andmethods for reducing or eliminating the negative impact on the engine orits delivery system from these natural products and bio-derivatives. Thepresent disclosure also provides improved protection of the fueldelivery system by the incorporation of certain fuel additives in thegasoline-ethanol fuel composition.

In one embodiment is provided a method to improve protection of a fueldelivery system in an internal combustion engine, said method comprisingdelivering to or combusting in said engine a fuel composition comprisinggasoline, ethanol and at least one fuel additive, said additive beingselected from the group consisting of succinimide dispersants,succinamide dispersants, amides, Mannich base dispersants, andpolyetheramine dispersants. Polyetheramines are particularly effectivein the compositions and methods of the present disclosure.

In another example the fuel additive is further selected from the groupconsisting of phenolics, hindered phenolics, aryl amines, and diphenylamines.

In yet another aspect herein, the fuel additive is further selected fromthe group consisting of monocarboxylic acids, dicarboxylic acids,polycarboxylic acids, p-phenylenediamine and dicyclohexylamine.Particularly useful herein as the acid fuel additives are tall oil fattyacids and/or the diacid dodecenyl succinic acid.

In yet another embodiment the fuel additive can be further selected fromthe group consisting of oxylated alkylphenolic resins, and formaldehydepolymer with 4-(1,1-dimethylethyl)phenol, methyloxirane and oxirane.

The fuel additive can be further selected from the group consisting ofmethyl cyclopentadienyl manganese tricarbonyl (“MMT”), cyclopentadienylmanganese tricarbonyl, azides, tetraethyl lead, peroxides and alkylnitrates.

The fuel additive can further be selected from ethylene oxide, propyleneoxide, butylene oxide, epoxides, C1-C8 aliphatic hydrocarbons, nitrousoxide, nitromethane and xylene.

The fuel additive is also further selected from the group consisting ofmonoesters, diesters, ethers, diethyl ether, ketones, diethers,polyethers, glymes and glycols.

In still another aspect the fuel additive is selected from the groupconsisting of monocarboxylic acids, dicarboxylic acids, andpolycarboxylic acids.

Also provided herein is a method of improving the protection of anengine combusting a fuel composition containing gasoline and ethanol,said method consisting essentially of combining the fuel and an additiveselected from the group consisting of driveability enhancing materialsthat include monoesters, diesters, ethers, ketones, diethers,polyethers, glymes and glycols, wherein the driveability of said engineis improved relative to the driveability of the engine combusting agasoline fuel without ethanol.

In another embodiment the fuel additive is selected from the groupconsisting of phenates, salicylates, sulfonates, nonylphenolethoxylates, fuel-soluble alkali detergents and alkaline earthmetal-containing detergents. Particularly effective detergents hereininclude phenates, salicylates, sulfonates, and nonylphenol ethoxylates.

Thus the present disclosure can be practiced by producing, conveying, orcombusting a fuel composition comprising, or in another embodimentconsisting essentially of, gasoline, ethanol and at least one fueldelivery system protecting agent, said agent being selected from thegroup consisting of succinimide dispersants, succinamide dispersants,amides, Mannich base dispersants, polyetheramine dispersants, phenolics,hindered phenolics, aryl amines, diphenyl amines, monocarboxylic acids,dicarboxylic acids, polycarboxylic acids, p-phenylenediamine anddicyclohexylarnine, oxylated alkylphenolic resins, formaldehyde polymerwith 4-(1,1-dimethylethyl)phenol, methyloxirane and oxirane, methylcyclopentadienyl manganese tricarbonyl, cyclopentadienyl manganesetricarbonyl, azides, tetraethyl lead, peroxides, alkyl nitrates,monoesters, diesters, ethers, diethers, diethyl ether, ketones,polyethers, glycols, glymes, oxiranes, C1-C8 aliphatic hydrocarbons,butylene oxide, propylene oxide, ethylene oxide, epoxides, butane,pentane, xylene, nitrous oxide, nitromethane, phenates, salicylates,sulfonates, nonylphenol ethoxylates, and fuel-soluble alkali detergentsand an alkaline earth metal-containing detergents.

Also provided herein is a fuel delivery system protecting agentconcentrate for gasoline engines combusting an ethanol-containing fuel,said concentrate comprising one or more fuel delivery system protectingagents and a diluent selected from the group consisting of an oil, afuel, gasoline, ethanol, solvent, carrier fluid, and other liquidmaterials combustible in a gasoline engine.

In one embodiment, the ethanol content of the fuel composition is fromabout 74% to about 85%. In another embodiment of the disclosure hereinthe ethanol content of the fuel composition is from about 50% to about74%.

EXAMPLES

TABLE 1 IVD Rig Test Deposits From E85 Fuels Ethanol Source Deposit, mg.New Energy Ethanol 1.6 ADM Ethanol 10.8 New Energy Ethanol is acommercial ethanol with a denaturant ADM Ethanol is ethanol with acorrosion inhibitor (DCI-11, from Innospec) and a denaturant

Table 1 shows the intake valve deposits generated on an Intake ValveDeposit simulator rig test using E85 fuels containing the ethanolsindicated. In this rig test, the fuel blend is sprayed onto a hotsurface and the resulting residue weighed. The base gasoline was CitgoRUL and without any additives the Intake Valve Deposit rating for thebase gasoline in the rig test was 12.4 mg. As can be seen, the twodifferent ethanol sources (New Energy and ADM) yielded significantdifferences, indicating a need for additives and a problem ofnon-uniformity across ethanol suppliers. While both ethanol productscontain a denaturant, the ADM Ethanol is further believed to have 32 PTBof a corrosion inhibitor known commercially as DCI-11 from Innospec. Ascan be seen by comparing the rig test deposits from these two ethanolswhen used in E85 gasoline-ethanol fuel blend, the ADM Ethanol generateda 10-fold increase in deposits relative to the deposits from the NewEnergy Ethanol. Such an E85 fuel will therefore need more detergents,dispersants and other additives than E85 fuels utilizing other ethanolsources to prolong the useful life of the engine and fuel deliverysystem.

TABLE 2 IVD Rig Test Deposits on E85 Fuel Containing Additives Dosage,Additive in ptb Deposit, mg H-4733 10 1.4 H-3000 25 0.9 H-4142 50 1.0H-4848A 50 12.7 H-4247 38 15.6 DDSA 50% 25 0.5 H-6560 100 4.0 AP-5000100 2.1 H-4705 20 1.5 GAR515A01 100 2.7 H-6457 50 2.7 H-4858 50 18.9H-6400 100 6.6 H-4103 5000 ppmv 0.4 H-4733 is 2,6-di t-butyl phenolantioxidant H-3000 is methylcyclopentadienyl manganese tricarbonylH-4142 is oleic acid plus N,N dimethylcyclohexylamine H-4848A isdiethanol amide, demulsifier, aromatic solvent H-4247 is succinimidedispersant and aromatic solvent DDSA 50% is dodecenyl succinic acid inA150 solvent H-6560 is Mannich base dispersant from dibutyl amineAP-5000 is BASF polyisobutylene amine dispersant H-4705 is 1,2 propanediamine salicylaldehyde metal deactivator GAR515A01 is a cresol Mannichdispersant from dibutyl amine; and polyol H-6457 is diethanol amide ofisostearic acid friction modifier H-4858 is ethylene glycol ester-basedlubricity additive H-6400 is polyetheramine and DDS corrosion inhibitor,Tolad demulsifier, Aromatic solvent H-4103 is 2-ethyl hexyl nitratecombustion improver Ptb is pounds per thousand barrelsTable 1 shows the intake valve deposits generated on the Intake ValveDeposit simulator rig test using E85 fuels containing the New EnergyEthanol. The dosage reported is the treat rate of the additive in thegasoline-ethanol fuel blend. As can be seen by comparing the rig testdeposits from these additives when used in the E85 gasoline-ethanol fuelblend, the deposits varied. However, it must be noted that (a) thistable used the ethanol contributing the lowest deposit level (New EnergyEthanol), so other ethanol sources, such as ADM Ethanol, will clearlyhave significantly more need for detergents, dispersants and other fueladditives, and (b) the deposits shown in Table 2 will include about 1.6mg of deposits from the New Energy Ethanol in the E85 fuel. Thus, for atleast those additives that generated deposits of about 2.7 mg or less,the total effective deposit not coming from the ethanol is essentiallyzero, that is, the present disclosure shows in at least theseembodiments virtually complete prevention of deposits and the resultingwear on the engine. These additives include 2,6-di t-butyl phenolantioxidant, methylcyclopentadienyl manganese tricarbonyl combustionimprover and octane enhancer, oleic acid plus N,Ndimethylcyclohexylamine, dodecenyl succinic acid, polyisobutylene aminedispersant, 1,2 propane diamine salicylaldehyde metal deactivator,cresol Mannich dispersant, diethanol amide of isostearic acid frictionmodifier, and 2-ethyl hexyl nitrate combustion improver. The alkylnitrate, 2-ethyl hexyl nitrate, was particularly effective in reducingdeposits and hence improving the protection of a fuel delivery system inthe engine combusting the E85 fuel blend.

Thus, there is provided herein a method of improving protection of afuel delivery system in an internal combustion engine combusting anethanol-gasoline blend, said method comprising combining the blend withat least one additive selected from the group consisting of 2,6-dit-butyl phenol antioxidant, methylcyclopentadienyl manganese tricarbonylcombustion improver and octane enhancer, oleic acid plus N,Ndimethylcyclohexylamine, dodecenyl succinic acid, polyisobutylene aminedispersant, 1,2 propane diamine salicylaldehyde metal deactivator,cresol Mannich base dispersant, diethanol amide of isostearic acidfriction modifier, and 2-ethyl hexyl nitrate combustion improver,whereby the deposits formed in said engine are less than the depositsformed in the engine when combusting the blend without the at least oneadditive.

In another example, a Keep Clean Test was performed by driving aChevrolet Impala for 5,000 miles using fuel containing gasoline withoutethanol, and fuel containing E85 blend. The Intake Valve Deposits (IVD)and the Combustion Chamber Deposits (CCD) were then measured and arereported in Table 3. The ethanol used in the E85 blend was ADM Ethanolexcept for Test No 6 where New Energy Ethanol was used.

TABLE 3 Keep Clean Test 5000 Miles IVD, CCD, Test No. Ethanol % H-6560,PTB mg mg 1 0 0 429 1232 2 0 85  5 1438 3 84  30/5 (1) 191 299 4 7485/22 (1) 134 265 5 84 0 227 184 6 84 0 99 176 7 84   500 (2) 4 277 (1)First number is treat rate in the gasoline, second number is treat ratein the finished blend. (2) H-6400 polyetheramine dispersant, not H-6560Table 3 illustrates the effect on deposits of having no ethanol (TestNo's 1 and 2) when used without and with (respectively) HiTEC® 6560, aMannich dispersant with a polyol and polyisobutylene carriers. The useof the dispersant reduced the IVD deposits from 429 mg to 5 mg. The E85fuel blend of Test No. 3 at a 5 PTB treat rate of the Mannich dispersantin the finished fuel had a IVD deposit of 191 mg but when the dispersantwas lacking from the E85 blend (Test No. 5), the IVD deposit went up to227, due in part to the contribution from the ethanol. Comparing TestNo. 3 and Test No. 4 also shows that reducing the ethanol content in thefuel blend from 84% to 74% reduced the deposits from 299 mg to 265 mg.This further illustrates that gasoline ethanol blends will need betterdispersancy and detergency. Test No. 6 used the New Energy Ethanol whichas shown in Table 1 contributes much less to deposits than does the ADMEthanol, so the IVD in Table 3 correspondingly shows only 99 mg ofdeposit. Test No. 7 shows the result from a higher treat rate (500 PTB)of a polyetheramine dispersant and the result when combusting the E85fuel was an amazingly low 4 mg of deposit, at least a major portion ofwhich can be attributed to the ethanol by comparing to Test No. 6.

For the CCD results of Table 3, comparing Test No. 3 (E85 plus theMannich dispersant) and Test No. 5 (E85 without the dispersant) one seesan improvement in reducing Combustion Chamber Deposits from 299 mg to184 mg and using the cleaner New Energy Ethanol of Test No. 6 reducedthe Combustion Chamber Deposit even further to 176 mg.

In this manner it is clear that the present disclosure provides a methodto improve protection of a fuel delivery system in an engine combustingan ethanol-containing fuel by adding to the fuel a polyetheraminedispersant or a Mannich dispersant. It is therefore expected that thecombination thereof will have similar or even enhanced and synergisticresults. The reduction of deposit formation is directly related toincreased longevity of the useful life of engine combustion surfaces,injectors, valves, gaskets, liners, seals, hoses, pumps, filters, andother fuel delivery system parts.

Example 1 Fuel Formulation with a Mannich Dispersant

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and a Mannich base fuel additive (HiTEC® 6560available from Afton Chemical Corporation, and having a PIB group with aMW of 950, and a cresol group reacted with dibutylamine). The fueladditive is present in the fuel composition at 200 ppm. The compositionis fed to and combusted in a direct injection gasoline engine. Theresulting fuel will demonstrate improved protection provided in thecombustion engine and fuel delivery system compared to the protectionresulting before and after combustion of a fuel composition notcontaining ethanol, as well as compared to the combustion of a fuelcomposition containing ethanol and gasoline but no Mannich base fueladditive.

Example 2 Fuel Formulation with a Succinimide Dispersant

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and an alkylated succinimide dispersant (HiTEC®4249 available from Afton Chemical Corporation, and having a PIB groupwith a MW of 950, and a maleic anhydride reacted with tetraethylenepentamine). The dispersant is present in the fuel composition at 100ppm. The composition is fed to and combusted in a spark ignited internalcombustion engine. The resulting fuel demonstrates improved protectionin an internal combustion engine and its delivery system compared to thecombustion of a fuel composition not containing ethanol, as well ascompared to the combustion of a fuel composition containing ethanol andgasoline but no alkylated succinimide dispersant.

Example 3 Fuel Formulation with a Phenolic Antioxidant

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and a phenolic driveability agent (HiTEC® 4733available from Afton Chemical Corporation and containing 2,4 di-t-butylphenol). The antioxidant is present in the fuel composition at 100 ppm.The composition is fed to and combusted in a gasoline engine. Theresulting fuel improves protection in an internal combustion engine andits fuel delivery system compared to the combustion of a fuelcomposition not containing ethanol, as well as compared to the deliveryand combustion of a fuel composition containing ethanol and gasoline butno phenolic antioxidant.

Example 4 Fuel Formulation with a Demulsifier

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and a demulsifier agent (Baker Petrolite's Tolad9372). The demulsifier agent is present in the fuel composition at 30ppm. The composition is fed to and combusted in an internal combustiongasoline spark ignited engine. The resulting fuel improves theprotection in an internal combustion engine and its fuel delivery systemcompared to the combustion and delivery of a fuel composition notcontaining ethanol, as well as compared to the combustion and deliveryof a fuel composition containing ethanol and gasoline but nodemulsifier.

Example 5 Fuel Formulation with a Dehazer

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and a dehazer agent (2-ethyl hexanol availablefrom BASF). The dehazer agent is present in the fuel composition at 5weight percent. The composition is fed to and combusted in an internalcombustion gasoline spark ignited engine. The resulting fuel improvesprotection in an internal combustion engine and its delivery systemcompared to the combustion and delivery of a fuel composition notcontaining ethanol, as well as compared to the combustion and deliveryof a fuel composition containing ethanol and gasoline but no dehazer.

Example 6 Fuel Formulation with an Octane Improver

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and a MMT octane improver (HiTEC® 3000 availablefrom Afton Chemical Corporation). The octane improver is present in thefuel composition at 300 ppm. The composition is fed to and combusted inan internal combustion engine. The resulting fuel improves protection inan internal combustion engine and its delivery system compared to thecombustion and delivery of a fuel composition not containing ethanol, aswell as compared to the combustion and delivery of a fuel compositioncontaining ethanol and gasoline but no MMT.

Example 7 Fuel Formulation with a Volatility Improver Agent

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and a volatility improving agent (2-ethyl hexylnitrate, HiTEC® 4103 available from Afton Chemical Corporation. Thevolatility improving agent is present in the fuel composition at 8weight percent. The composition is fed to and combusted in a gasolineengine. The resulting fuel improves protection in an internal combustionengine and its delivery system compared to the combustion and deliveryof a fuel composition not containing ethanol, as well as compared to thedelivery and combustion of a fuel composition containing ethanol andgasoline but no volatility improving agent.

Example 8 Fuel Formulation with a Detergent

A fuel composition is prepared by combining gasoline (15% by volume) andethanol (85% by volume) and a detergent agent (HiTEC® 611 available fromAfton Chemical Corporation, and having an overbased calcium sulfonate).The detergent agent is present in the fuel composition at 2.5 weightpercent. The composition is fed to and combusted in an internalcombustion engine. The resulting fuel improves protection in an internalcombustion engine and its delivery system compared to the delivery andcombustion of a fuel composition not containing ethanol, as well ascompared to the delivery and combustion of a fuel composition containingethanol and gasoline but no detergent agent.

Other embodiments of the present disclosure will be apparent to thoseskilled in the art from consideration of the specification and practiceof the disclosure disclosed herein. As used throughout the specificationand claims, “a” and/or “an” may refer to one or more than one. Unlessotherwise indicated, all numbers expressing quantities of ingredients,properties such as molecular weight, percent, ratio, reactionconditions, and so forth used in the specification and claims are to beunderstood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the specification and claims are approximations that mayvary depending upon the desired properties sought to be obtained by thepresent disclosure. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of theclaims, each numerical parameter should at least be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques. Notwithstanding that the numerical ranges andparameters setting forth the broad scope of the disclosure areapproximations, the numerical values set forth in the specific examplesare reported as precisely as possible. Any numerical value, however,inherently contains certain errors necessarily resulting from thestandard deviation found in their respective testing measurements. It isintended that the specification and examples be considered as exemplaryonly, with a true scope and spirit of the disclosure being indicated bythe following claims.

1. A method to improve protection of a fuel delivery system in aninternal combustion engine, said method comprising delivering to orcombusting in said engine a fuel composition comprising gasoline,ethanol and at least one fuel additive, said additive being selectedfrom the group consisting succinimide dispersants, succinamidedispersants, amides, Mannich base dispersants, and polyetheraminedispersants.
 2. The method of claim 1, wherein the fuel compositioncomprises at lease one second fuel additive, said additive beingselected from the group consisting of phenolics, hindered phenolics,aryl amines, and diphenyl amines.
 3. The method of claim 1, wherein thefuel composition comprises at lease one second fuel additive, saidadditive being selected from the group consisting of monocarboxylicacids, dicarboxylic acids, p-phenylenediamine and dicyclohexylamme. 4.The method of claim 1, wherein the fuel composition comprises at leaseone second fuel additive, said additive being selected from the groupconsisting of oxylated alkylphenolic resins, and formaldehyde polymerwith 4-( 1,1 -dimethylethyl)phenol, methyloxirane and oxirane.
 5. Themethod of claim 1, wherein the fuel composition comprises at lease onesecond fuel additive, said additive being selected from the groupconsisting of methyl cyclopentadienyl manganese tricarbonyl,cyclopentadienyl manganese tricarbonyl, azides, tetraethyl lead,peroxides and alkyl nitrates.
 6. The method of claim 1, wherein the fuelcomposition comprises at lease one second fuel additive, said additivebeing selected from the group consisting of monoesters, diesters,ethers, ketones, diethers, polyethers, glymes and glycols.
 7. The methodof claim 1, wherein the fuel composition comprises at lease one secondfuel additive, said additive being selected from the group consisting ofmonocarboxylic acids, dicarboxylic acids, and polycarboxylic acids. 8.The method of claim 1, wherein the fuel composition comprises at leaseone second fuel additive, said additive being selected from the groupconsisting of phenates, salicylates, sulfonates, nonylphenolethoxylates, fuel-soluble alkali detergents and aikaline earthmetal-containing detergents.
 9. A fuel composition comprising gasoline,ethanol and at least one fuel delivery system protecting agent, saidagent being selected from the group consisting of succinimidedispersants, succinamide dispersants, amides, Mannich base dispersants,polyetheramine dispersants, phenolics, hindered phenolics, aryl amines,diphenyl amines, monocarboxylic acids, dicarboxylic acids,polycarboxylic acids, p-phenylenediamine, dicyclohexylamine, oxylatedalkylphenolic resins, formaidehyde polymer with 4-( 1,1-dimethylethyl)phenol, methyloxirane and oxirane, methylcyclopentadienyl manganese tricarbonyl, cyclopentadienyl manganesetricarbonyl, azides, tetraethyl lead, peroxides, alkyl nitrates,monoesters, diesters, ethers, dieters, ketones, polyethers, glycols,glymes, oxiranes, C1-C8 aliphatic hydrocarbons, butylene oxide,propylene oxide, ethylene oxide, epoxides, butane, pentane, xylene,nitrous oxide, nitromethane, phenates, salicylates, sulfonates,nonyiphenol ethoxylates, fuel-soluble alkali detergents and an alkalineearth metal-containing detergents.
 10. A fuel composition consistingessentially of gasoline, ethanol and at least one fuel delivery systemprotecting agent, said agent being selected from the group consisting ofsuccinimide dispersants, succinamide dispersants, amides, Mannich basedispersants, polyetheramine dispersants, phenolics, hindered phenolics,aryl amines, diphenyl amines, monocarboxylic acids, dicarboxylic acids,polycarboxylic acids, p-phenylenedianiine and dicyclohexylamine,oxylated alkylphenolic resins, formaldehyde polymer with 4-( 1,1 -dimethylethyl)phenol, methyloxirane and oxirane, methyl cyclopentadienylmanganese tricarbonyl, cyclopentadienyl manganese tricarbonyl, azides,tetraethyl lead, peroxides, alkyl nitrates, monoesters, diesters,ethers, dieters, polyethers, glycols, glymes, oxiranes, C1-C8 aliphatichydrocarbons, butylene oxide, propylene oxide, ethylene oxide, epoxides,butane, pentane, xylene, nitrous oxide, nitromethane, phenates,salicylates, sulfonates, nonyiphenol ethoxylates, fuel-soluble alkalidetergents and alkaline earth metal-containing detergents.
 11. Thecomposition of claim 9, wherein the ethanol content of the fuelcomposition is from about 74% to about 85%.
 12. The composition of claim9, wherein the ethanol content of the fuel composition is from about 50%to about 74%.
 13. The composition of claim 10, wherein the ethanolcontent of the fuel composition is from about 74% to about 85%.
 14. Thecomposition of claim 10, wherein the ethanol content of the fuelcomposition is from about 50% to about 74%.
 15. A method of improvingthe protection of an engine combusting a fuel composition containinggasoline and ethanol, said method consisting essentially of combiningthe fuel and an additive selected from the group consisting ofmonoesters, diesters, ethers, ketones, diethers, polyethers, glymes andglycols, wherein the protection of said engine is improved relative tothe protection of the engine combusting a gasoline fuel without ethanol.16. A method of improving the protection of an engine combusting a fuelcomposition containing gasoline and ethanol, said method comprisingcombining the fuel and an additive selected from the group consisting ofsuccinimide dispersants, succinamide dispersants, amides, Mannich basedispersants, polycteramine dispersants, phenolics, hindered phenolics,aryl amines, diphenyl amines, monocarboxylic acids, dicarboxylic acids,polycarboxylic acids, p- phenylenediamine and dicyclohexylamine,oxylated alkylphenolic resins, formaldehyde polymer with 4-( 1,1-dimethylethyl)phenol, methyloxirane and oxirane, methylcyclopentadienyl manganese tricarbonyl, cyclopentadienyl manganesetricarbonyl, azides, tetraethyl lead, peroxides, alkyl nitrates,monoesters, diesters, ethers, ketones, diethers, polyethers, glycols,glymes, oxiranes, C1-C8 aliphatic hydrocarbons, butylene oxide,propylene oxide, ethylene oxide, epoxides, butane, pentane, xylene,nitrous oxide, nitromethane, phenates, salicylates, sulfonates,nonyiphenol ethoxylates, thel-soluble alkali detergents and alkalineearth metal- containing detergents, wherein the protection of saidengine is improved relative to the protection of the engine combusting agasoline fuel without ethanol.
 17. The method of claim 3, wherein themonocarboxylic acid is a tall oil fatty acid.
 18. The method of claim 3,wherein the dicarboxylic acid is dodecenyl succinic acid.
 19. The methodof claim 16, wherein the monocarboxylic acid is a tall oil fatty acid.20. The method of claim 16, wherein the dicarboxylic acid is dodecenylsuccinic acid.
 21. A fuel delivery system protecting agent concentratefor gasoline engines combusting an ethanol-containing fuel, saidconcentrate comprising one or more fuel delivery system protectingagents and a diluent selected from the group consisting of an oil, afuel, gasoline, ethanol, solvent, carrier fluid, and other liquidmaterials combustible in a gasoline engine.